1. Field of the Invention
This invention relates generally to the testing of semiconductor devices, and typically to a packaged semiconductor device, which may comprise a semiconductor die and a chip carrier such as a package substrate or tape. The semiconductor device may be mounted to or inserted onto a contactor board, which may be a socket or contactor used for testing the functionality or reliability of the semiconductor device. Due to the possibility of improper seating, misalignment or improper orientation of the semiconductor device relative to the contactor board, proper electrical coupling between the semiconductor device and the contactor board should be verified upon mounting of the semiconductor device onto the contactor board.
Areas of interest are electrical and/or reliability testing of the semiconductor device, or performing any test or qualification that involves a semiconductor device mounted to or inserted onto a contactor board.
2. Description of the Related Art
During the testing of a semiconductor device, it is necessary that a semiconductor device and a contactor board have the proper physical contact between an array of electrically conductive elements, or electrically conductive elements, on an exposed face of the semiconductor device and a facing array of electrically conductive elements on the contactor board. The proper physical contact implies that the semiconductor device and the contactor board have a predetermined relative orientation such that the two arrays of electrically conductive elements are in the correct relative position to complete the requisite electrical circuit for testing the semiconductor device.
In addition, a problem can be that a portion of the electrically conductive elements of the two arrays may be in proper contact, but the remainder of the electrically conductive elements may register an open circuit. The condition can exist when the semiconductor device is tilted with respect to the contactor board such that only a portion of the two arrays are in physical contact. In this configuration, only a portion of the two arrays will have the requisite electrical contact. As a result, the reason for which the semiconductor device and contactor board are electrically coupled is compromised. Further, powering up or applying an electrical current through an improperly coupled semiconductor device and contactor board may electrically and/or mechanically damage the semiconductor device. This damage may be obvious, resulting in a financial loss, or marginal, resulting in the danger that a marginally damaged semiconductor device of lower reliability is delivered to a customer.
Referring to FIG. 1A through FIG. 1C, the physical contact and non-contact of an array of electrically conductive elements 110 located on a semiconductor device 100 with an array of electrically conductive elements 210 of a contactor board 200 is illustrated. In FIG. 1A, the proper alignment of the contactor board 200 and the semiconductor device 100 is illustrated. In this relative positioning, substantially all of the electrically conductive elements 110 of the semiconductor device 100 are in contact with the electrically conductive elements (not shown) on contactor board 200. In FIG. 1B, the semiconductor device 100 is not in correct physical contact with the contactor board 200. Consequently, only the electrically conductive elements 110 along the edge of the semiconductor device 100 may be in contact with the electrically conductive elements 210 on contactor board 200. FIG. 1C illustrates a different positioning problem wherein only an edge row of electrically conductive elements 110 of the semiconductor device 100 may be in contact with the electrically conductive elements 210 of the contactor board 200. As will be clear, when the array of electrically conductive elements 110 between the semiconductor device 1 and contactor board 200 are not in physical and electrical contact, then the electrical conductivity between the semiconductor device 100 and the contactor board 200 may not present.
Referring to FIG. 2, a cross-section view is shown of the contactor board 200 comprising an associated array of electrically conductive elements 210 and a semiconductor device 100 comprising an array of electrically conductive elements 110 is shown. A semiconductor die 400 is shown located within the semiconductor device 100 and may be mounted on the chip carrier 500.
When the semiconductor device 100 and the contactor board 200 are placed in physical contact, at least two problems may occur. The first problem, illustrated on FIG. 1A through FIG. 6D, may present itself because the array of electrically conductive elements 110 and 210 are typically a square array, and therefore, the orientation of the semiconductor device 100 relative to the contactor board 200 may easily be in error, as the semiconductor device 100 and contactor board 200 may be rotated relative to one another. If this erroneous relative rotation occurs, at least a portion of the electrically conductive elements 110 from the semiconductor device 100 and at least a portion of the electrically conductive elements 210 of the contactor board 200 may be in physical contact. However, if the electrically conductive elements 110 and 210 are not in physical and electrical contact in the expected orientation, then the application of an improper voltage will not only result in the spurious operation, but the application of incorrect voltage to the semiconductor die can cause damage to the circuits therein.
A second problem that may present itself is illustrated in FIG. 1A through FIG. 1C. When facing surfaces of the semiconductor device 100 and the contactor board 200 are not substantially parallel, then at least a portion of electrically conductive elements 110 may not be in contact with the corresponding electrically conductive elements 210. This lack of electrical contact can result in spurious operation.
Consequently, a need has been felt for an apparatus and an associated method for determining the relative orientation between a semiconductor device and a contactor board, each having an array of electrically conductive elements. It would be yet another feature of the apparatus and associated method to provide a technique for verifying the proper electrical conductivity between the array of electrically conductive elements of the semiconductor device and the array of electrically conductive elements of the contactor board.
It is a more particular feature of the present invention to have embedded electrically conductive elements in the semiconductor device and the contactor board such that, when the array of electrically conductive elements on the semiconductor device and the array of electrically conductive elements on the contactor board are in physical contact, a complete electrical circuit is completed. It would be yet a more particular feature of the present invention to provide a technique by which a simple electrical measurement can verify a predetermined relative orientation between a semiconductor device and a contactor board and the electrical conductivity between the arrays of electrical elements.